package com.ypj.community.service;

import com.ypj.community.domain.User;
import com.ypj.community.util.CommunityConstant;
import com.ypj.community.util.RedisKeyUtil;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.dao.DataAccessException;
import org.springframework.data.redis.core.RedisOperations;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.SessionCallback;
import org.springframework.stereotype.Service;

import java.util.*;

@Service
public class FollowService implements CommunityConstant {
    @Autowired
    private RedisTemplate redisTemplate;
    @Autowired
    private UserService userService;

    public void follow(int userId, int entityType, int entityId) {
        redisTemplate.execute(new SessionCallback() {
            @Override
            public Object execute(RedisOperations operations) throws DataAccessException {
                String followeeKey = RedisKeyUtil.getFolloweeKey(userId, entityType);
                String followerKey = RedisKeyUtil.getFollowerKey(entityType, entityId);

                operations.multi();

                operations.opsForZSet().add(followeeKey, entityId, System.currentTimeMillis());
                operations.opsForZSet().add(followerKey, userId, System.currentTimeMillis());
                return operations.exec();
            }
        });
    }
    public void unfollow(int userId, int entityType, int entityId) {
        redisTemplate.execute(new SessionCallback() {
            @Override
            public Object execute(RedisOperations operations) throws DataAccessException {
                String followeeKey = RedisKeyUtil.getFolloweeKey(userId, entityType);
                String followerKey = RedisKeyUtil.getFollowerKey(entityType, entityId);

                operations.multi();

                operations.opsForZSet().remove(followeeKey, entityId);
                operations.opsForZSet().remove(followerKey, userId);

                return operations.exec();
            }
        });
    }
    //关注数量
    public long findFolloweeCount(int userId,int entityType){
        String followeeKey=RedisKeyUtil.getFolloweeKey(userId,entityType);
        return redisTemplate.opsForZSet().zCard(followeeKey);
    }
    //查询粉丝数量
    public long findFollowerCount(int entityType,int entityId){
        String followerKey=RedisKeyUtil.getFollowerKey(entityType,entityId);
        return redisTemplate.opsForZSet().zCard(followerKey);
    }
    //查询当前用户是否已关注
    public boolean hasFollowed(int userId,int entityType,int entityId){
        String followeekey=RedisKeyUtil.getFolloweeKey(userId,entityType);
        return redisTemplate.opsForZSet().score(followeekey,entityId)!=null;
    }
    //查询某用户关注的人
    public List<Map<String,Object>> findFollowees(int userId,int offset,int limit){
        String followeeKey=RedisKeyUtil.getFolloweeKey(userId,ENTITY_TYPE_USER);
        Set<Integer> targetIds=redisTemplate.opsForZSet().reverseRange(followeeKey,offset,offset+limit-1);
        if (targetIds==null){
            return null;
        }
        List<Map<String,Object>> list=new ArrayList<>();
        for (Integer targetId:targetIds){
            Map<String,Object> map=new HashMap<>();
            User user=userService.findUserById(targetId);
            map.put("user",user);
            Double score=redisTemplate.opsForZSet().score(followeeKey,targetId);
            map.put("followTime",new Date(score.longValue()));
            list.add(map);
        }
        return list;
    }
    //查询某用户粉丝
    public List<Map<String,Object>> findFollowers(int userId,int offset,int limit){
        String followerKey=RedisKeyUtil.getFollowerKey(ENTITY_TYPE_USER,userId);
        Set<Integer> targetIds=redisTemplate.opsForZSet().reverseRange(followerKey,offset,offset+limit-1);
        if (targetIds==null){
            return null;
        }
        List<Map<String,Object>> list=new ArrayList<>();
        for (Integer targetId:targetIds){
            Map<String,Object> map=new HashMap<>();
            User user=userService.findUserById(targetId);
            map.put("user",user);
            Double score=redisTemplate.opsForZSet().score(followerKey,targetId);
            map.put("followTime",new Date(score.longValue()));
            list.add(map);
        }
        return list;
    }

}
